Bifurcation and Periodicity in Granular Soils: Implicationsto Geomechanics and Hazard Mitigation

该项目将建造一个内部的，长度依赖的塑料 颗粒材料理论应用于研究 不稳定现象。 分析、数值和实验 将对这一概念进行评估，以确定 这种方法提供的信息的增长和波 相关变形不均匀性的长度选择。 的 内部长度尺度将通过Cosserat- 以应力不对称为特征的类型修改，或 梯度依赖项表征了 塑性流动法则 这两种方法的优点和缺点将 将被检查和最简单的可能形式将被用来研究 三类与危险有关的问题：剪切带、表面 不稳定和液化。 这项工作将提供更好的 了解物理故障过程， 发展的根本 适当的缓解措施。

The project will construct an internal, length-dependent plastic theory for granular materials to be applied to the study of instability phenomena. Analytical, numerical and experimental evaluation of this concept will be conducted to determine the ability of this approach to provide information on the growth and wave length selection of the associated deformation inhomogeneities. The internal length scale will be introduced either through a Cosserat- type modification characterizing the assymetry of stress, or a gradient-dependent term characterizing the heterogeneity of the plastic flow-rule. The merits and drawbacks of both approaches will be examined and the simplest possible form will be used to study three classes of hazard-related problems: shear banding, surface instabilities, and liquefaction. This work will provide a better understanding of the physical failure processes which are fundamental for the development of appropriate mitigation measures.